It’s 4 am on a mid-August morning in the northern California wilderness. During a brief overnight storm, lightning strikes the top of a hill, ignites some dry underbrush, and starts a wildfire. It isn’t until 6am as the sun rises that someone notices the fire—a hiker camping an overlooking hill. As soon as the hiker’s 911 call is received by the emergency dispatch center they contact Cal Fire—the agency responsible for wildfire protection and management in California. By 6:30, they call the Redding, California-based smokejumpers. They are one of the most elite firefighting squads in the United States. There are only 400 smokejumpers in the USand 40 of those are based here in Redding, California.
They’re essentially the rapid response team for wildfires. Within 15 minutes of receiving the call, these smokejumpers are in their plane and taking off. It takes just 20 minutes to fly the 50 miles to the fire site where they find a suitable tree-free landing spot, jump, deploy their parachutes and land. The plane then circles back to parachute down boxes of equipment. Smokejumpers carry with them enough supplies to last 72 hours completely self-supported—food, water, shelter, safety equipment, and fire fighting tools. They follow the ridgeline and make their way to the fire. Now, this is a small team and they need to decide how to prioritize what they do. With the fire already had grown to 15 acres the team knows they’re unlikely to stop it on their own, backups are already on the way, so their priority is to slow it down as much as possible. There are four major factors that affect how fast a fire moves: how much fuel there is, how wet the fuel is, the wind direction, and the slope. The two factors that the team can immediately gauge that affect where the fire will move the fastest are the wind direction and slope. In this case, the wind is coming from the north and they know that to the south-west is an upward slope. Fire moves faster uphill than it does downhill since fire burns upwards so these smokejumpers know that this is likely the fire’s fastest-moving front. While trees do burn, the primary source of fuel that a wildfire uses to move is the dry brush and deadwood on the forest floor so the biggest technique used to stop forest fires is to create what’s called a fireline. These are essentially a gap where they remove all fuel—plants both dead and alive—so that there’s nothing for the fire to continue burning. The smokejumpers use a mix of chainsaws and other hand tools to do this work but sometimes fire lines are pre-built. In this case, there’s a road at the top of the uphill section which will help slow or stop the fire so they can direct their efforts elsewhere. They use the road as their anchor point—a cleared section that the fire likely won’t cross where they start building their fireline so the fire can’t outflank them. Throughout this construction process, the smokejumpers need to be sure that they can escape in case the winds shift or the fire picks up speed. Wildfires can move exceptionally fast—up to 7 miles per hour in forests which is faster than humans are often able to make their way through dense trees. In grasslands, fires can move up to 14 miles per hour so firefighters have to be extra cautious. For this reason, firefighters rarely put themselves directly in front of the fire’s moving front—they’ll either be far ahead or to the side. In the case of this fire as they’re building this first fire line they’re close to a road which acts as an easy exit point but, just in case, all smokejumpers carry fire shelters. These compact, lightweight shelters won't survive direct flames for too long, but they do greatly increase a firefighter’s chance of survival in case they can’t escape the path of the fire. After a little over an hour of work,
the smokejumpers complete a continuous fire line from the road to a stream. Streams, while less secure than roads, also help stop or slow down a fire by acting as a fire line. To the south-east of the fire there’s also a small road that connects to another stream meaning there are at least rudimentary firelines on three sides of the fire. It’s at this time when backups arrive byroad. The added manpower allows for much faster action. The immediate focus goes to strengthening the southeastern fire line—currently just a stream. At the closest the fire’s less than 100 feet from the stream and the stream is itself in a valley so it’s too risky to work directly behind the stream, there’s just no good escape route, so the new arrivals get to work on a redundant fire line 100 feet behind the stream. By 10 am the fire has further grown and the team knows that the worst is still to come. Fires spread most rapidly between 10am and sunset due to the daytime heat and wind. By 11am the fire has reached the road and part of the fire line which means that some of those that we're building the fire-line are re-allocated to make sure that the fire-line holds—extinguishing any flames that may jump the road. By noon the fire lines are holding and, while the fire’s size is growing, it’s at a manageable pace so there’s reasonable hope that it can be suppressed before expanding to an uncontrollable size. At 1pm, though, conditions change. The wind starts blowing harder towards the south-west and, as trees burn on the north side of the road, the wind pushes embers over the road which ignite underbrush on the other side and now the entire focus of the firefighting efforts change. You see, the point of fighting wildfires is not actually to put them out, it’s to control them. While the number of wildfires has increased due to humans they’re actually a very natural phenomenon. What’s making wildfires worse is humans stopping them. Many forests survive wildfire through trees having heat-resistant bark and other evolutionary adaptations. These fire-resistant forests relied on having wildfires at a consistent interval every few decades to clear out the forest floor of dead plants and to kill invasive species. Nowadays, though, as humans suppress fires a forest might only see a wildfire every 50 years instead of 25, for example, meaning that there’s twice as much fuel and so the fire burns faster, larger, and more intensely. It was only until recent years that the research revealing this was widely accepted so the goals of firefighting shifted from stopping wildfires completely to controlling them. In some places, being a firefighter actually means starting fires. Fire management agencies will conduct controlled burns in order to reduce the risk of an uncontrollable fire and to increase the health of a forest. While forests can survive wildfires, humans can not so most agencies will let fires burn in a controlled fashion up until the moment they risk damaging property or threatening human life. This fire that jumped the road just did exactly that. At the bottom of this slope is a town andthe fire is now headed in that direction with no preexisting features to stop it. That means that all measures must be taken to aggressively stop the fire’s expansion to the west. That means it’s time to bring out the big guns—it’s time to attack the fire from above. Planes and helicopters are some of the most effective tools used to fight wildfires. They can quickly and accurately drop huge amounts of water or fire retardant. The decision to use aerial firefighting does not come lightly as it’s both hugely expensive and using an aircraft on one fire means it can't be used on another. Their use needs to be prioritized to the most dangerous fires. There’s also a decision to be made on what the aircraft is going to drop—water or flame retardant. Water is cheap and, with some aircraft designs, can be reloaded near the fire without landing at an airport. Water is only effective at extinguishing flames, though. Flame retardant, on the other hand, can be used to stop flames from starting. It can essentially create a fire line ahead of the fire’s spread as it will stop a line of the forest from burning. The main issues, though, are that flame retardant can only be loaded at an airport and it’s very expensive. A gallon of Phos-Chek, the most commonly used brand of flame retardant, costs $3. That’s about the same as a gallon of milk at the grocery store but these aircraft use thousands of gallons of it for each drop. The world’s largest firefighting aircraft, the 747 supertankers, for example, carries 19,600 gallons of flame retardant meaning that what it uses in one drop costs nearly $60,000. Of course, there’s a reason agencies hire this plane, it creates a 3-mile long fire line almost instantly, but it comes at a steep price. For this fire, using such an expensive tool would be overkill. In this case, they’ll use a helicopter with a bucket attached. The bucket is filled with water from a nearby lake then the helicopter flies over to the fire and drops it. With only 5 miles to the lake, the helicopter is able to make a drop about every 5-10 minutes and, while it works on stopping the spread on one side hand crews work on building a fire line on the other.
The area that the helicopter extinguishes essentially acts as its own fire line as fire can’t burn what’s already burned. This work continues for the next few hours—it's vital to not let anything to the south-west of the road burn out of control. By 4pm the outbreak is managed and attention can be directed back to the largest section of the fire. As the afternoon wears on some crews get back to lengthening the eastern fire line, others begin constructing a western fire line, andthe helicopter works on slowing the advancement to the north. By the time the sun begins to set around 8, all sides of the fire have at least some element of control so that during the night and in the coming days the fire can continue to burn in a controlled fashion until there’s nothing left to burn. This mission was a success but the reality is that this is not a real fire. Real fires rarely end this well. Real fires don’t act so predictably because real fires can’t be predicted. Real fires are a menace that can grow to the size of small countries and can burn for months. During summer and fall, there are often more than 100 large forest fires burning around the US at any given time and thousands more around the world. No firefighting effort is exactly like another but these are the primary techniques used by those who work every day to protect life and property from one of nature’s most dangerous phenomenons. Whether you’re fighting forest fires or running a business the tools you use are crucially important. In both cases, they directly affect how well you do your job and, while chainsaws, axes, and shovels are some of the most important tools in firefighting.
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